David Morrison woke up on the train the way he always woke up on the train: disoriented, for exactly three seconds, before the familiar grey ceiling of the L train resolved itself above him and the sound of wheels on tracks filled his ears and he remembered where he was and what day it was and that it was Tuesday and Tuesday meant another day of data and spreadsheets and the endless small humiliations of being a man who analyzed other people's behavior for a living while his own life proceeded at the speed of molasses in January.

He got off at 14th Street and walked the rest of the way to his apartment in Brooklyn, which was a studio that cost too much and had a window that looked at another window and a kitchen that consisted of a microwave and a mini-fridge and a sink that dripped. He lived there because it was close to the train, and the train was close to Manhattan, and Manhattan was where he worked, and work was what he did, and doing was what people did in New York because if you stopped doing for too long you might start thinking and if you started thinking you might realize that you were thirty years old and you had never done anything that you would remember and you were spending your life moving numbers from one column to another and calling it a career.

He fell asleep that night at 11:30, which was early for him, because the default routine was: come home, eat something from the microwave, scroll through his phone until his eyes burned, fall asleep, wake up, repeat. But that night, something interrupted the routine. A sound, maybe. Or the absence of a sound. The city outside his window, which never stopped making noise--cars, sirens, the distant hum of a million lives living at maximum volume--went quiet for exactly one second, and in that second of silence, David felt something pull, like a thread being drawn through fabric, and then the noise came back and he was asleep and the thread was gone.

He woke up on the ground.

Not on the train. Not in his apartment. On the ground, which was soft and damp and covered in something that looked like moss but smelled like ferns, and above him was a sky the color of polished copper, and above that sky, visible through gaps in a canopy so high he could barely see it, were trees that were not trees as he understood them. They were taller than any trees in Central Park, thicker than the columns of St. Patrick's, their trunks rising straight for a hundred feet without a single branch, and their canopies, wherever they were, were so far above that the sunlight reached the ground in thin golden shafts, like the interior of a cathedral built by someone who understood scale in a way that New York never had.

David sat up. The moss beneath him was cool and slightly springy, and when he pressed his hand into it, it yielded and then slowly returned to its original shape, like memory.

He was alone. Or he thought he was. He stood up and turned in a circle and saw nothing but trees and moss and the golden shafts of light, and the air, which was the most remarkable thing of all. It was warm and humid and smelled of wet earth and crushed leaves and something sweet, like the inside of a greenhouse after rain. It was the smell of a place that had never known a car or a building or a human being, and it hit David in the chest like a physical thing, because he had not smelled anything this clean since he was a boy and his grandmother had a garden in New Jersey and the air in July had smelled exactly like this.

He walked. He did not know where he was going, and he did not care, because for the first time in his adult life, the question of where he was going did not matter. There was no data to analyze. There was no spreadsheet to fill. There was only the moss under his feet and the golden light through the trees and the smell of a world that did not know his name.

He saw the first one at noon, or what he assumed was noon, because the light had shifted slightly and the golden shafts were lower and warmer, like the light in a room in the late afternoon.

It was moving through the trees ahead of him, slowly, deliberately, and it was the size of a school bus and it was covered in feathers that were the color of autumn leaves--bronze and gold and burnt orange--and it had a neck that was long and flexible and a head that was small and birdlike and eyes that were dark and round and when it looked at him, it looked at him the way a person looks at something unexpected but not threatening, the way you look at a dog in your backyard that you did not know was there.

David stopped walking. The creature stopped moving. They regarded each other across a clearing of moss and ferns and golden light, and David felt something in his chest loosen, like a knot he had been carrying for thirty years had finally, impossibly, begun to untie.

He did not run. He did not scream. He stood still, which was the hardest thing he had ever done, because every instinct he had--every instinct his species had, going back sixty-six million years to the moment our ancestors first scurried between the dinosaur feet in terror--told him to run.

But he did not run. And the creature, after a long moment, turned and moved on, its feathered body swaying gently, its feet making no sound on the moss, and David stood there and watched it disappear into the trees and felt something he could not name and did not have a word for and would spend the rest of his life trying to name.

He returned to his apartment that night through the thread. He did not know how it worked. He did not know what triggered it. He only knew that when he lay down on his narrow bed in his studio apartment in Brooklyn and closed his eyes and let the silence come--not the silence of the city, which was never silent, but the silence underneath the city, the silence that lived in the space between one breath and the next--the thread would appear, and he would follow it, and he would be back in the moss, under the copper sky, among the feathered creatures that looked at him without fear and moved through the trees without hurry and existed, simply and completely, in a way that David Morrison, data analyst, thirty years old, had never existed in his entire life.

He began to count the days. One night in the other world was roughly equal to one night in this one. The thread was consistent in that way. He could go to sleep in his apartment and wake up in the moss, and he could sleep in the moss and wake up in his bed. The transition was seamless, like stepping through a door he could not see but could feel, the way you feel a door you cannot see when you are walking down a hallway and you know it is there because the wall has changed texture or the light has shifted.

He started bringing things. A notebook, which he filled with sketches of the feathered creatures and notes about their behavior. A camera, which produced blurry, useless photographs that showed only green and gold and shadow, as if the other world did not want to be captured. A small knife, which he never used, because there was nothing to cut and nothing to defend himself against and nothing in that world that required a knife.

He started staying longer. One night became two. Two became three. He began to miss things in his apartment--not the apartment itself, which was small and expensive and meaningless, but the routine. The microwave dinners. The phone scrolling. The train to Manhattan. He missed them the way you miss a habit you know is bad for you but cannot give up, because the habit is the only thing holding the structure of your life together.

But the other world was pulling him more each night, and the feathered creatures were becoming less mysterious and more familiar, and the moss was becoming the ground he recognized and the copper sky was becoming the ceiling he expected, and he was spending more time in a world that did not exist and less time in a world that did, and he was beginning to understand what existence meant and whether it was measured by presence or by attention or by the simple fact of being somewhere with your whole self, not just your body but the thing inside your body that you call yourself and that you have spent your entire life trying to convince is real.

The door began to fail in March. He went to sleep in his apartment and followed the thread to the moss and stood in the copper light and looked at the feathered creatures and felt the familiar loosening in his chest, and then the thread pulled back, sharply, like a rubber band snapping, and he was in his apartment again, and the city was loud, and the microwave was humming, and the phone was lighting up with messages from people he did not care about, and the door was gone.

He waited. He went to sleep and woke up and the door was still gone. He went to sleep again and woke up and the door was still gone. He lay in his bed in the dark and listened to the city and felt something he had not felt since he was a boy and his grandmother's garden in New Jersey had been sold to a developer and the trees had been cut down and the house had been replaced by a parking lot and he had stood there with his grandmother and watched the trees fall and understood, for the first time, that some doors, once closed, never open again.

On the seventh night, the door opened. But it was different. It was narrower, dimmer, less certain. And when he stepped through it, the other world was quieter than he remembered. The feathered creatures were there, but they moved more slowly, and their feathers were duller, and when they looked at him, their eyes were not dark and round but tired and old and knowing, as if they had been waiting for him and had been waiting a long time and were tired of waiting.

David stood in the moss and looked at the copper sky and understood, with a certainty that sat in his chest like a stone, that the door would not stay open. That the two worlds were not meant to share a boundary, that the friction between them was wearing both down, that the other world was changing because he was in it, the way his world had changed because he was in it, the way every presence changes the presenceless, the way every visitor changes the visited, the way every act of attention changes the thing that is attended to.

He stood at the threshold of the door, which was narrowing even as he stood there, and he looked at the feathered creatures, and he looked at the world behind him, the world of data and spreadsheets and microwaves and trains and apartments that cost too much and looked at other windows, and he made a choice, not because it was heroic or meaningful or the kind of choice that changes the course of history, but because it was his choice, and in a life that had consisted almost entirely of choices made for him by circumstance and necessity and the slow grinding machinery of being a man in a city that did not care whether he lived or died, this was his choice, and it was small and personal and entirely his own, and that was enough.

He stepped through.